Four patients tested positive, and now, the clinic is shut down and patients urged to get tested for both hepatitis and HIV.

Timothy Morley, an osteopathic doctor, runs a practice called Tomorrow Medicine with locations in Mount Kisco and White Plains.

"For me to encounter this in my own life is crazy," patient Isa Santiago said. "I'm just scared."

She knows better because she works in the health care field educating teenagers about HIV prevention, and now, she is among those who will be tested for exposure to potentially deadly illnesses.

"It's kind of like surreal for me right now," she said.

Morley has a significant online presence, as well, offering weight loss treatment, hormone therapy and nutrition counseling. Health officials are urging anyone who had blood drawn or an infusion to be tested. Both offices was closed Tuesday, and his building co-tenant among those expressing surprise.

"It's shocking," business owner Julia Moore said. "It's a little upsetting. I'm sure they'll do the right thing. I hope they'll do the right thing."

Health officials say it's not clear exactly how the virus was spread, but drawing from the same vial of medicine or vitamins to inject multiple patients is a possible cause. Westchester County is offering free screenings for those who might have been exposed.

That includes Santiago, who said the news is disheartening since she experienced great success under Dr. Morley, losing nearly 50 pounds.

"Hearing this from a friend and living this today is really scary," she said. "And I feel really bad that I referred to Dr. Morley and his practice."

The state Health Department is now pursuing charges against the doctor.

Eyewitness News reached out to Dr. Morley's office for comment, but has not heard back.